The overall objective is to further investigate how a protein acquires its native conformation which gives rise to its unique biological functions. Specifically, we plan study the following aspects of protein folding employing carbonic anhydrases. (1) Preparation and characterization of active fragments and their complements; followed by equilibrium and kinetic studies of their unfolding and refolding. (2) Metal ion-protein interaction and its role in the formation of active site in metalloenzymes, including the possibility of trapping and characterizing of folding intermediates by metal ions coordination. The results of these studies will provide fundamental knowledge on possible environmental causes of abnormalities of proteins to clinical and biomedical researchers particularly those working in the field of respiratory diseases since carbonic anhydrase is one of the essential enzymes involved in this important physiological function.